Prescription opioid abuse is the fastest growing form of opiate/opioid abuse in the United States. Most of these medications come from prescriptions written for pain. There is controversy as to the risk of abuse and addiction when chronic non-malignant pain is treated by prescription opioids. The risk of developing abuse or addiction has never been studied in a longitudinal fashion among patients of primary care physicians who initiate most of the opioid treatment. Some experts advise against the use of opioid analgesics in this population because they believe that tolerance soon renders the medication ineffective and the risk of addiction is high while others say that addiction is rare among pain patients and that analgesia continues over time. Neither side has longitudinal studies with appropriate measures to support their arguments. In any case, the medications are being widely prescribed because pain is ubiquitous and the physicians who initiate the greatest number of patients on this treatment are primary care physicians. We propose to study the treatment of pain in a large sample (600 patients) of typical primary care patients who are ethnically diverse to determine whether pain relief continues over 24 months and what is the frequency of aberrant behaviors leading to abuse or addiction. End points will be based on the DSM diagnosis of abuse or addiction. We will carefully measure baseline factors that are thought to increase risk of addiction such as history of substance abuse, family history and presence of psychiatric disorders such as depression and anxiety. We will also monitor prescribing practices of the 92 primary care physicians who have volunteered to be included in the study. Patients with a history of substance abuse will not be excluded because these patients also have chronic pain and at present there are no evidence-based guidelines on the increased risk of abuse posed by these patients nor what methods can be used to treat their pain adequately without the appearance of abuse or relapse. Our ultimate goal is the prevention of abuse and the improvement of pain treatment. During the final year of this five year project, we will begin to apply the information learned from the longitudinal study to develop a package of treatment guidelines that can be tested in a subsequent randomized, controlled trial against treatment as usual (as defined by our observational study). These treatment guidelines, tailored to the needs of primary care physicians, will be disseminated in meetings and journals as described in our current program to bring awareness of substance abuse to mainstream medicine.